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An AAV9 coding for frataxin clearly improved the symptoms and prolonged the life of Friedreich ataxia mouse models.

Gérard C, Xiao X, Filali M, Coulombe Z, Arsenault M, Couet J, Li J, Drolet MC, Chapdelaine P, Chikh A, Tremblay JP - Mol Ther Methods Clin Dev (2014)

Bottom Line: This mutation leads to a reduced expression of frataxin.We have produced an adeno-associated virus (AAV)9 coding for human frataxin (AAV9-hFXN).The human frataxin protein was detected by ELISA in the heart, brain, muscles, kidney, and liver with the higher dose of virus in both mouse models.

View Article: PubMed Central - PubMed

Affiliation: Centre de Recherche du Centre Hospitalier Universitaire de Québec and Department of Molecular Medecine, Faculty of Medecine, Laval University , Québec, Canada.

ABSTRACT
Friedreich ataxia (FRDA) is a genetic disease due to increased repeats of the GAA trinucleotide in intron 1 of the frataxin gene. This mutation leads to a reduced expression of frataxin. We have produced an adeno-associated virus (AAV)9 coding for human frataxin (AAV9-hFXN). This AAV was delivered by intraperitoneal (IP) injection to young conditionally knockout mice in which the frataxin gene had been knocked-out in some tissues during embryogenesis by breeding them with mice expressing the Cre recombinase gene under the muscle creatine kinase (MCK) or the neuron-specific enolase (NSE) promoter. In the first part of the study, different doses of virus were tested from 6 × 10(11) v.p. to 6 × 10(9) v.p. in NSE-cre mice and all leading to an increase in life spent of the mice. The higher and the lower dose were also tested in MCK-cre mice. A single administration of the AAV9-hFXN at 6 × 10(11) v.p. more than doubled the life of these mice. In fact the MCK-cre mice treated with the AAV9-hFXN were sacrificed for further molecular investigations at the age of 29 weeks without apparent symptoms. Echography analysis of the heart function clearly indicated that the cardiac systolic function was better preserved in the mice that received 6 × 10(11) v.p. of AAV9-hFXN. The human frataxin protein was detected by ELISA in the heart, brain, muscles, kidney, and liver with the higher dose of virus in both mouse models. Thus, gene therapy with an AAV9-hFXN is a potential treatment of FRDA.

No MeSH data available.


Related in: MedlinePlus

Detection of the hFXN transgene in various tissues of muscle creatine kinase (MCK)-cre. (a) The human frataxin (hFXN) transgene was detected by polymerase chain reaction (PCR) not only in the DNA of muscles (M), L (liver), heart (H), kidney (K), and brain (B) of the mice injected with AAV9-hFXN at 6 × 1011 v.p. (on the left) but also the expression of human frataxin (on the right). (b) Finally, an ELISA test (Dipstick) was made to detect the human FXN protein in the tissues of MCK-cre mice treated with AAV9-hFXN at 6 × 1011 v.p. (named AAV9-hFXN; n = 8) and at 6 × 109 v.p. (named d1/100; n = 4). The presence of human frataxin was strongest with the highest viral doses and decreased in all tissues with the dilution.
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fig6: Detection of the hFXN transgene in various tissues of muscle creatine kinase (MCK)-cre. (a) The human frataxin (hFXN) transgene was detected by polymerase chain reaction (PCR) not only in the DNA of muscles (M), L (liver), heart (H), kidney (K), and brain (B) of the mice injected with AAV9-hFXN at 6 × 1011 v.p. (on the left) but also the expression of human frataxin (on the right). (b) Finally, an ELISA test (Dipstick) was made to detect the human FXN protein in the tissues of MCK-cre mice treated with AAV9-hFXN at 6 × 1011 v.p. (named AAV9-hFXN; n = 8) and at 6 × 109 v.p. (named d1/100; n = 4). The presence of human frataxin was strongest with the highest viral doses and decreased in all tissues with the dilution.

Mentions: The presence of the virus was detected by PCR in genomic DNA (Figure 6a on the left) and by RT-PCR (Figure 6a on the right) following a treatment with 6 × 1011 v.p. As for NSE-cre mice, the strongest band was observed for the heart tissue. The presence of human frataxin protein was also detected with the dipstick method (Figure 6b). Following the injection of 6 × 1011 v.p. of AAV9-hFXN, the presence of frataxin was observed in all tissues tested, the stronger bands being in muscle, liver, and heart. Following the administration of 6 × 109 v.p., the human frataxin protein was still observed in all the organs except in the brain where no protein was detected. However, the frataxin concentrations were lower than following the administration of the higher quantity of virus.


An AAV9 coding for frataxin clearly improved the symptoms and prolonged the life of Friedreich ataxia mouse models.

Gérard C, Xiao X, Filali M, Coulombe Z, Arsenault M, Couet J, Li J, Drolet MC, Chapdelaine P, Chikh A, Tremblay JP - Mol Ther Methods Clin Dev (2014)

Detection of the hFXN transgene in various tissues of muscle creatine kinase (MCK)-cre. (a) The human frataxin (hFXN) transgene was detected by polymerase chain reaction (PCR) not only in the DNA of muscles (M), L (liver), heart (H), kidney (K), and brain (B) of the mice injected with AAV9-hFXN at 6 × 1011 v.p. (on the left) but also the expression of human frataxin (on the right). (b) Finally, an ELISA test (Dipstick) was made to detect the human FXN protein in the tissues of MCK-cre mice treated with AAV9-hFXN at 6 × 1011 v.p. (named AAV9-hFXN; n = 8) and at 6 × 109 v.p. (named d1/100; n = 4). The presence of human frataxin was strongest with the highest viral doses and decreased in all tissues with the dilution.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4362356&req=5

fig6: Detection of the hFXN transgene in various tissues of muscle creatine kinase (MCK)-cre. (a) The human frataxin (hFXN) transgene was detected by polymerase chain reaction (PCR) not only in the DNA of muscles (M), L (liver), heart (H), kidney (K), and brain (B) of the mice injected with AAV9-hFXN at 6 × 1011 v.p. (on the left) but also the expression of human frataxin (on the right). (b) Finally, an ELISA test (Dipstick) was made to detect the human FXN protein in the tissues of MCK-cre mice treated with AAV9-hFXN at 6 × 1011 v.p. (named AAV9-hFXN; n = 8) and at 6 × 109 v.p. (named d1/100; n = 4). The presence of human frataxin was strongest with the highest viral doses and decreased in all tissues with the dilution.
Mentions: The presence of the virus was detected by PCR in genomic DNA (Figure 6a on the left) and by RT-PCR (Figure 6a on the right) following a treatment with 6 × 1011 v.p. As for NSE-cre mice, the strongest band was observed for the heart tissue. The presence of human frataxin protein was also detected with the dipstick method (Figure 6b). Following the injection of 6 × 1011 v.p. of AAV9-hFXN, the presence of frataxin was observed in all tissues tested, the stronger bands being in muscle, liver, and heart. Following the administration of 6 × 109 v.p., the human frataxin protein was still observed in all the organs except in the brain where no protein was detected. However, the frataxin concentrations were lower than following the administration of the higher quantity of virus.

Bottom Line: This mutation leads to a reduced expression of frataxin.We have produced an adeno-associated virus (AAV)9 coding for human frataxin (AAV9-hFXN).The human frataxin protein was detected by ELISA in the heart, brain, muscles, kidney, and liver with the higher dose of virus in both mouse models.

View Article: PubMed Central - PubMed

Affiliation: Centre de Recherche du Centre Hospitalier Universitaire de Québec and Department of Molecular Medecine, Faculty of Medecine, Laval University , Québec, Canada.

ABSTRACT
Friedreich ataxia (FRDA) is a genetic disease due to increased repeats of the GAA trinucleotide in intron 1 of the frataxin gene. This mutation leads to a reduced expression of frataxin. We have produced an adeno-associated virus (AAV)9 coding for human frataxin (AAV9-hFXN). This AAV was delivered by intraperitoneal (IP) injection to young conditionally knockout mice in which the frataxin gene had been knocked-out in some tissues during embryogenesis by breeding them with mice expressing the Cre recombinase gene under the muscle creatine kinase (MCK) or the neuron-specific enolase (NSE) promoter. In the first part of the study, different doses of virus were tested from 6 × 10(11) v.p. to 6 × 10(9) v.p. in NSE-cre mice and all leading to an increase in life spent of the mice. The higher and the lower dose were also tested in MCK-cre mice. A single administration of the AAV9-hFXN at 6 × 10(11) v.p. more than doubled the life of these mice. In fact the MCK-cre mice treated with the AAV9-hFXN were sacrificed for further molecular investigations at the age of 29 weeks without apparent symptoms. Echography analysis of the heart function clearly indicated that the cardiac systolic function was better preserved in the mice that received 6 × 10(11) v.p. of AAV9-hFXN. The human frataxin protein was detected by ELISA in the heart, brain, muscles, kidney, and liver with the higher dose of virus in both mouse models. Thus, gene therapy with an AAV9-hFXN is a potential treatment of FRDA.

No MeSH data available.


Related in: MedlinePlus